This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A073279 #14 Jan 26 2023 12:15:53
%S A073279 1,1,1,5,34,250,2058,18661,185695,2017527,23804069,303413813,
%T A073279 4157895295,60989187252,953766105164,15844435971349,278704524938621,
%U A073279 5175632136205088,101198102131888304,2078318050691940125,44731639502987747576,1006917859088311808499
%N A073279 Number of digits of n!^n! (ultrafactorial numbers).
%F A073279 a(n) = floor(log(n!^n!)/log(10)) + 1.
%t A073279 Table[1 + Floor[n!*Log10[n!]], {n, 0, 21}] (* _Arkadiusz Wesolowski_, Oct 13 2012 *)
%o A073279 (PARI) for(n=0,8,print1(length(Str(n!^n!)),","))
%Y A073279 Cf. A046882 (ultrafactorial numbers), A000142 (n!), A034886 (digits of n!).
%K A073279 base,nonn
%O A073279 0,4
%A A073279 _Rick L. Shepherd_, Jul 23 2002
%E A073279 More terms from _Arkadiusz Wesolowski_, Jul 04 2012
%E A073279 Terms a(17) to a(21) corrected by _Arkadiusz Wesolowski_, Oct 13 2012